Platelet-Count-Guided Low Molecular Weight Heparin Management of Catheter-Related Thrombosis in a Large Cohort of Patients with Newly Diagnosed Acute Leukemia

Abstract Treatment of catheter-related thrombosis (CRT) in acute leukemia patients is challenging due to concomitant thrombocytopenia. Although modified-dose anticoagulation is frequently used in this setting, several vital outcomes remain unclear. The current study evaluated clinical outcomes of a platelet-count-guided low molecular weight heparin (LMWH) regimen in these patients. Data on all newly diagnosed acute leukemia patients, who developed CRT, were retrieved from the institutional database. Upon CRT diagnosis, patients received either a full or modified dose of LMWH, based on their platelet counts. Outcomes included recurrent venous thromboembolism (VTE), hemorrhagic events. Competing risk analyses were performed, with death considered a competing risk. All-cause mortality and blood product utilization (per patient; pre- and postanticoagulation commencement) were compared. A total of 193 acute leukemia patients diagnosed with CRT between November 2004 and May 2022 were included. Eighty-seven patients (45%) received full-dose LMWH. Modified-dose LMWH treatment was associated with hazard ratio (HR) of 0.642 (95% confidence interval [CI]: 0.268–1.540; p = 0.320) in terms of CRT recurrence and HR of 0.975 (95% CI: 0.439–2.170; p = 0.950) in terms of hemorrhage. Mortality was not significantly higher in the modified-dose group (HR: 1.47, 95% CI: 0.93–2.32; p = 0.092). Notably, platelet requirement did not differ before and after the CRT diagnosis, irrespective of LMWH doses used (full-dose group: median pre-CRT 0.09 [interquartile range, IQR: 0–0.27] vs. post-CRT 0.05 [IQR: 0.01–0.14] units/day, p = 0.059; modified-dose group: median pre-CRT 0.03 [IQR: 0–0.24] vs. post-CRT 0.07 [IQR: 0.01–0.18] units/day, p = 0.720). In acute leukemia patients with CRT, a platelet-count-guided LMWH regimen was not associated with higher rates of recurrent VTE, hemorrhagic complications, mortality, or platelet transfusion requirements.